Automatic variable speed transmission



Oct. 9, 1945. E ss 2,386,217

AUTOMATIC VARIABLE SPEED TRANSMISSION Filed July 10, 1940 6 Sheets-Sheetl R? 3 1 6 [2? [F72 z y" 1 5 M I H. I 9 r? 26 M I I 1 64 89 81 72 81 [7I 66 70 o 97 3 .56 90 83 71 84 2 1 Win 57 l U .aw 67 i v' 68 O f a I 5 ma f &3 ;.93 7% 92 69 57 111 J: L5 10 g 94 69 95 [n z/ en for Mom/1fKEG/P5355 Oct. 9, 1945. A. KEGRESSE AUTOMATIC VARIABLE SPEEDTRANSMISSION6 Sheets-Sheet 2 Filed July 10, 1940 f M222 for ADOLPHE KEG/9155515 Oct.9, 1945. A. KEGRESSE AUTOMATIC VARIABLE SPEED TRANSMISSION Filed July10, 1940 6 Sheets-Sheet 3 In men for Oct. 9, 1945. A. KEGRESSE 2,385,217

AUTOMATIC VARIABLE SPEED TRANSMISSION Filed July 10, 1940 6 Sheets-Sheet4 [nyen for 51 A004 P// KEG, 15555 Oct. 9,1945. A KEGRESS 2,386,217

AUTOMATIC VARIABLE SPEED TRANSMISSION Filed July 10, 1940 6 Sheets-Sheet6 [)2 2/612 of 400mm. EG/P550:

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Patented Oct. 9, 1945 AUTOMATIC VARIABLE SPEED TRANSMISSION AdolpheKgresse, Paris, France; vested in the Allen Property CustodianApplication July 10, 19%, Serial No. 344,826 in France duly 28, 1939(Cl. ll-330) ll) @laims.

This invention relates to an automatic variable speed transmission theoperation of which can be varied by hand.

This mechanism is characterised by great facility of manufacture and anappreciable reduction in the cost price, and also by its small bulk ascompared with similar transmissions. It is applicable to all machinesusing change speed ears and more particularly to automobile vehicles ofall kinds, to the motor-cycle, to motor rail vehicles, tractors, and thelike.

' Theknown and practically used gears, termed automatic change-speedgears" or semi-auto matic change speed gears" are all special devices ofa greater weight and bulk than the usual change speed gears. They aremore ,difllcult to make and necessitate a considerable number of newmachine tools. Furthermore, most of them are not complete, that is tosay, that their operation is not absolutely automatic and requires, forexample, a de-clutching controlled by pedal for the starting andstopping Or the manipulation of a knob or handle to operate them.

The apparatus forming the subject of the invention is of the type withtwo clutches mounted on concentric shafts and controlling constantmeshgears. These latter are driven by the shafts by means of dog clutches ofthe synchromesh type or the like.

It comprises essentially four groups of distinct members, each of themforming a system which, united to the others, again gives a compactwhole. These groups are:

l. A block of two multi-disc clutches, compressed hydro-mechanically,the fluid used "being preferably lubricating oil.

2. A hydraulic system comprising: a pump, cylindersand pistonscontrolling the clutches, a distributor of fluid to the clutches, adouble automatic and hand selector and also valves and distribution anddischarge slide valves.

3 The change-speed gear proper, which contains the clutches and theircoupling devices.

4. The automatic running regulator with the controls.

The apparatus replaces with advantage, for example on an automobile, theclutch and the change-speed gear as at present and permits of definitelyeliminating the clutch pedal and the change-speed lever.

The vehicle, apart from the steering, is then controlled with a singlefoot which acts either on the accelerator to increase or maintain thespeed, or on the brake to obtain a slowing down or the stopping of thevehicle.

, and clutches of the change-speed gear can generally be used. Theadvantage of being able to use existing parts gives a supplementaryguarantee of good operation, since these parts already proved on currentmodels will be free from the risks always tcbe feared in the case ofnewly designed mechanisms. In any case, the invention permits of the usealmost entirely of existing machine tools.

Each of the above-mentioned groups of members presents more particularlythe following characteristics:

l. A single block, centred on the principal axis and integral with thecasing, contains the whole of the hydraulic portion. This block will behereinafter termed the hydraulic body. It permitsof doing away entirelywith tubing under pressure, thus avoiding, together with the risks ofleakages at the jointsand breakages always to be feared, the lengths ofpiping prejudicial to rapid I operation It furthermore permits ofconsiderably reducing the difilculties of assemblage.

2. The feed of the annular clutch-operatin piston, which maybe replacedby a simple diaphragm, takes place at the moment of starting, bytransit, that is to say, that the engine running slowly, thefluidtraverses diametrically the cylinder of the annularclutch-operating piston, to escape outwards through a centrifugal valvearranged to this end opposite the delivery valve. This permits with theleast movement of the accelerator, of obtaining complete engagementsince, when running on no load, all the dead spaces are filled with oilwhich is flowing. This point is most important since, withoutinstantaneous starting, no transmission of any kind can bepractical.

3. The feed of fluid to the clutch block has been eifected by an"extensible distributor mounted on the hydraulic body and being appliedagalnst the clutch block under the effect of a portion of the pressureof the fluid, which pressure acting equally on the extensible walls ofthe distributor itself, radically does away with any risk of leakagewithout nevertheless preventing the distributor from following the smallaxial displacement due to play and to expansions. This distributor,taking up less space than those hitherto used, does not sufier like themunder the influence of wear. v

4. The arrangement of the single pump, located in the hydraulic body,itself extremely simplifled, its drive by the engine, eflected by meansof a toothed sleeve. Furthermore, its body being integral with the samepart as the other hydraulic members, the distance to be travelled by thefluid is much reduced, which ensures a rapidity of operation which hasnot existed in'the case of similar devices, the slow action of which iswell known.

5. The speed selector, an essential member of the apparatus presents anovel and simplified solution of the selection of speeds. It comprisestwo concentric slide valves of equalised pressure. One of these, thecentre one, is controlled by the regulator mounted on the driven shaft;it assures the automatic operation. The outer slide valve is controlledby hand and permits, if the driver desires, of retaining a selectedspeed, the lower speeds remaining always subject to the action of theregulator, when the speed of the engine is no longer sufllcient tosupport the selected speed. The spring and the resistance of theregulator are arranged for given speeds which correspond to thecharacteristics of the engine. In principle, these characteristics areselected to correspond to the lowest practically utilisable speed of theengine, for each gear ratio. A supplementary locking preferablycontrolled by the accelerator pedal in the second half of its stroke,presents the possibility, with an insignificant effort, in spite of thehigh thrusts due to centrifugal forces, of considerably retarding theactionof the regulator, thus permitting of prolonging the period ofrunning in each speed, without supplementary manipulation. This featureis e specially advantageous in starting, which it makes more powerful,and also on inclines.

6. It is known that in the case of entirely automatic transmissions, itis impossible when stopping on a downward slope to hold back the car bymeans of the engine. In the same way, the engine cannot be started bythe car. This is one of the many defects of these transmissions.

According to the invention, when at rest one of the clutches iscompresse by springs, so that it is sllfllcient, by hand. to engage oneof the speeds corresponding to this engagement, in order to obtain thesame result as with ordinary automobiles.

7. The cylinders and pistons controlling the dog clutches are grouped oneach side of the selector, from which they receive the oil underpressure. They are double acting. One of them controls the uneven speedsof one of the friction clutches; the first by one face, the third by theother face; the other controls the even speeds of the second frictionclutch, under the same conditions.

The cylinders and pistons of the dog clutches are also used for thedistribution of oil under pressure to the clutches, in such manner thatthe operation of the latter depends on the displacement of the first.

The friction clutches cannot come into operation until after the dogclutches, so that wrong manipulation is impossible.

8. Practical experience of clutches using a pressure of oil has shownthat it is absolutely tual gear casings being already at the limit ofheight above the ground.

This result is obtained according to the invention by a simple sumparranged at the lower part of the clutch block, between the latter andthe gear case. This sump i provided with an incurved "scraper" fittingto within 1 or 2 mm. the

conditions as on cars with shape of the outline of the clutch block. Theeifect of the scraper is to deliver the oil entrained by the clutchblock to the exterior of the sump, that is to say, into the gear caseitself.

The invention may be applied to transmissions comprising any number ofspeeds either with the driven shaft in the prolongation of the engineshaft, or with the driven shaft arranged in a different plane. only, theconstruction may he considerablyj-simplified owing to the fact that thesecond speed is connected directly and only on one of the two clutchplateswhich rotates idly in the first and third speed. It will be notedthat, in this case, the corresponding pinions operate under the samesynchromesh" change-speed gears.

. Other features of the invention will appear from the followingdescription given in explanation of the annexed drawings which show byway of example, a'practical embodiment.

In these drawings:

Figure l is a longitudinal section of the whole transmission, thesection being on the line AOB of Figure 2;

Figure 2 is a cross-section on the line C-D of Figure l, the clutchesbeing removed;

Figure 3 shows two half sections on the lines E-F and G-I-I of Figure l,the clutch plates being removed;

Figure 4 is a section on the line I-J-K oi Figure 3;

Figure 5 is a section on the line K-L of Figure 3;

Figure 6 is a section on a larger scale on the line M-N of Figures 1 and8;

Figure 7 is a section on the line P-Q of ure 6 Figure 8 is a section onthe line R-S-T of Figure Figure 9 is a section on the line UV of Figure'6;

Figure 10 is a section of the hydraulic body, the moving members beingremoved;

Figure 11 isa section on the line O-Z-S-V of Figure 6;

Figures 12 and 13 show in elevation and in section the distributor offluid to the clutches;

Figure 14 shows on a larger scale, the regulator and its control;

Figure l5, i6, 17, 18 and 19 show diagrammatically the respectivepositions of the slide valve and of the double selector. In these fig-Figspeeds obtained.

Figure 20 is a diagram of a three-speed gear 1:;

For a three-speed transmission 6 above Figure 21 is a diagram of afive-speed gear box.

The gear case of ordinary construction is indicated by I. 2 is theengine shaft and 3 the driven shaft. On the engine shaft 2 is fixed thegroup of the two clutches which comprisesv a flywheel 6, a plate 5movable axially, a distributor plate 6 fixed to the flywheel 4 by aseries of bolts 1. The movable plate 5 has at its periphery a series ofteeth 8 (Figure 3) which engage freely in corresponding recesses of therim of the distributor plate 6.

On its face opposite to the engine the distributor plate receives anannular piston 9, made tight on its large diameter by piston rings it.On its small diameter an elastic piston ring of suitable shape lidensures a tight joint and the locking of the piston at the neutralposition. On its large diameter this piston is provided with lugs iithrough which pass bolts or rods l2 connecting the annular piston to themovable plate 5. A series of springs l3 operating in compression tend toseparate the movable plate 5 from the plate 8 fixed to the flywheel bybolts '5. Two clutch plates and 15 are arranged on the one hand betweenthe movable plate 5 and the flywheel d and, on the other hand, betweenthe second plate of the movable plate 5 and the distributor plate 6.

The latter has, close to its hub, an annular channel 16 (Figures 1, 3, 5and 9) communicating with a conduit 11 bored in the plate 6. Thisconduit ll terminates at the periphery of the plate the speed valve l8,provided with a callbrated spring 19 (Figures 3 and 4). This type ofvalve counterbalanced with respect to centrifugal force is described inUnited States Patent Number 2,163,202, granted June 20, 1939. It ensuresthe control of the annular piston 9 through the conduit 20 (Figure 4),and the evacuation of the oil through the orifice 2|.

Diametrically opposite this valve and on the same plate 6, is arranged acylindrical plug 22 (Figures 3 and 5) adapted to slide freely in itsrecess. This plug is pressed towards the centre by a calibrated spring23. The small chamber formed at the top of the plug when the latter isnearest the centre (position of Figures 3 and 5) communicates on the onehand with the cylinder of the annular piston 9, through the conduit 24,

and on the other hand with the exterior, through the orifice 25.

The hydraulic body 26 is fixed to the casing I. It may be made in asingle piece with this casing without thereby changing in any way thecharacter of the invention. The hydraulic body 26 centralises all thehydraulic operations of the system. It contains the pump 21' (Figures 6and 9), here provided with blades 28, which is driven by the tubularshaft 29 and the dog clutches 30 (Figures 1, 4, 5 and 9) provided in theinterior of the hub of the clutch plate 6 rotating with the flywheel 4.

The admission of oil to the pump 21 takes place through a tube 31 whichdescends into the lower portion of the casing i. The pump delivers theoil through the conduit 32 (Figures 6 and 9) to the interior of thedouble selector 33 (Figures 8, 9 and 11). The latter is composed of asliding sleeve 34 and a hollow cylinder 35 closed at its twoextremities.

The sliding sleeve 34. is controlled by hand from the drivers seatthrough the usual system of rods acting on the double lever 36. Theouter extremity of the sleeve 34 has a series of locking channels 31each of which corresponds to a speed; a supplementary channelcorresponds to the "stop" position. A bolt 88 serves to fix the sleeve34 at the speed selected by the driver. Towards its centre the sleeve 34has a perforated channel 39 of such length that in all its positions itpermits the oil coming from the conduit 32 to reach the centre of theselector. 0n the side opposite to the locking channels, the sleeve 34 isprovided with other perforated channels 46 which are calibrated and eachof which corresponds to a speed. The last channel opens into a chamber Mthe function of which will be described later.

The hollow cylinder 55, closed at its two extremities, is, controlleddirectly by the centrifugal governor (Figure 14) through the rod 14!.The latter has over some portion of its length, a series of lockingchannels 52 (Figure 14:) also corre-. sponding to the number of thespeeds. A bolt 65 creates a. more or less strong resistance to thelongitudinal displacement of the hollow cylinder 35. To this end, thetension of the spring of the bolt may be modified by the driverpreferably through the accelerator pedal which is connected by means ofa usual rod system to the elbow lever 55. The hollow cylinder 35 admitsthe oil at its centre through a bored longitudinal channel 5t similar tothe channel 39 of the sleeve 34. The

oil can only escape from the hollow cylinder 35,

through openings into a single exterior calibrated channel 61 (Figure 8)which places the interior of the hollow cylinder 35, through perforatedchannels 30 of the sleeve 36 in communication with the passages 48 madein the hydraulic body 26 also calibrated and distributing the oil aswill be seen below.

For the better understanding of the operation, these passages 18, shownat the position which they actually occupy on Figure 8 are representedon the same plane in the diagrammatic Figures 15, 16, 17, 18 and 19,where they are indicated by l, 2, 3, 6.

The passages 48 (Figure 8) each open into a small separate chamber, 49for the first speed, 50

for the second speed, 5| for the third speed, and V 52 for the fourthspeed. A channel 53 provided in the interior of the body 33 of theselector leads the oil to the stop" position between-two calibratedvalves 54 and 55 (Figure 11) one of these, 54, the spring of which isweaker, leads to the chamber 56 (Figure 9) of the distributor 51 (Figure13); the other, 55, is compressed by a spring the calibrated tension ofwhich corresponds to half the working pressure of the oil. Thedistributor 51 is constituted by a hollow ring with thin walls 58(Figures 12 and 13). Its single rigid face 59 is bored with holes 60which permit of placing the chamber 56 in communication with the channell6 which supplies the conduit 11 of the clutch plate 6. The deliveryconduit 32 of the pump (Figure 9) is provided with a discharge valve 6|with spring 62 limiting the pressure of oil to the desired rate ofworking.

There appertain furthermore to the hydraulic body 26, two oil-tightcylinders 63 and 64 (Figrures 6 and 8) in each of which a piston 65 and66 can move. The rod 61 of the piston 65 has a fork 68 which controlsthe dog clutch sleeve 69 mounted on the secondary shaft of the changespeed gear (Figure 1). The rod II! of the piston 66 has the fork H whichcontrols the dog'clutch sleeve 12 mounted on the principal shaft of thechange speed gear box.

Each of the cylinders 63 and 64 communicates through a small conduit 13opening into the centre of each cylinder with a push piece 14 (Figures 6and '1) carrying a needle 'I5 which tegral with the shaft.

closes another small conduit 18 opening at the centre of the adjacentcylinder. A spring 11 calibrated to the maximum pressure of the oilbears against the push piece 18 and the needle 18. An orifice 18 placeseach of the needles 15 in communication with the exterior. Anotherorifice 18 also places the chamber 88 of each push piece 14 incommunication with the exterior as soon as the push piece moves.

Springs 8| (Figures 1 and 8) arranged on each side of the forks 88 and1| tend to bring the pistons 88. 88 and their forks 88 and 1| to theneutral point (position of the figure).

The change speed gear itself trains of gears in constant mesh tern ofdog clutches.

The reverse drive alone usual change-speed gears, by the displacement ofa pinion.

The clutch disc I4 is provided with grooves and slides axially onsplines on a central shaft 82 (Figure l) which controls the second andfourth speeds. The disc I5 is mounted in the same way on'the tubularshaft 88 controlling the first and third speeds.

The extremity of the shaft 82 opposite to the disc it engages freely inthe driven shaft 3. Near the latter the shaft 82 has a splined portionon which slides the hub 84 of the clutch dog sleeve 12. The latter canbe placed in engagement, by means of the piston 88, its rod' 18, and itsfork 1|, either with the pinion 85 mounted freely on the shaft 82. orwith the toothed wheel 88 integral with the driven shaft 3. The pinion85 engages with the wheel 81 integral with the gear 88. both beingintegral with the secondary shaft. The toothed wheel 88 is in constantmesh with the gear 88 on the driven shaft.

The tubular shaft 83 terminates at the side opposite to the disc I5 by agear-wheel 88 in- A pinion 88 mounted on a splined portion of thetubular shaft 83 can be moved axially on this latter by hand control inthe ordinary way. This pinion 88 engages in forward running with thewheel 8I freely mounted on the secondary shaft. This wheel carries dogclutch teeth 82. The gear-wheel 88 is in constant mesh with the oppositegear-wheel 88 mounted also freely on the secondary shaft; the lattergear-wheel also has dog clutch teeth 84.

Between the toothed wheels 8| and 83 there is provided a dog clutchblock 88 which, sliding on a splined portion of the secondary shaft, canbe placed in engagement through the piston 85, its rod 81 and the fork88 either with the dog clutch 82 of the gear 8| or with the dog clutch84 of the gear 83.

The dog clutch block 88 difiers from the other one by having externalteeth 85 which mesh with a pinion 88 represented diagrammatically onFigure 2, in order to obtain in a known manner a reverse drive by meansof the hand controlled sliding pinion 88.

A centrifugal governor represented on a larger scale on Figure 14 isdriven by the shaft 3. It is arranged at the exit of the change-speedgear, between the two roller bearings supporting the shaft 8 and doesnot therefore require any special support. It comprises masses 81 hingedat 88 and their syson arms 88 forming the rotating body of the governor.A sliding sleeve I88 has on the outside two channels, one of'which, I8|. is acted upon by the masses 81 and the other, I82, transmits thisaction to the hinged lever I83 which, through its extremity opposite tothe governor,

comprises the 2 is obtained, as in the.

' oppose the displacement 88 as shown on Figures acts through the grooveI88 on the rod IlI integral with the hollow cylinder of the selector.The sliding sleeve I88 has on the inside a groove I85 in which a springring I88 (Figure ll) can move. This ring can engage consecutively in aseries of grooves I81 of increasing depth, starting from thatcorresponding to the stop position and the number of which is the sameas that of the speeds. These grooves I81 are provided on the hub I88 ofthe governor. The distance of the grooves from each other correspondsexactly to that of the grooves 42 of the rod I and this distance apartis also that of the apertures 88 and 88 of the selector 38 (Figure 15),and of its sleeve 84. the grooves 31 of which are also at the samedistance apart. Springs I88 and H8 (Figure 14) of unequal strength andlength of the sleeve I88. Between the gear block and the lower part ofthe casing I there is provided a pan III (Figures 1 and 3) fixed to thecasing. This pan has a scraper H2 at a distance of 1 or 2 mm. from theperiphery of the gear block and the section of which is similar to thefixed blade of a turbine. An aperturev H3 is provided in the wall of thepan just below the scraper II2, to place the interior of the pan incommunication with the cas- The apparatus described operates as follows:

The car being stopped and the dog clutches not in engagement, the enginerunning slowly drives the pump 21 which through the conduit 82 deliversoil to the interior of the selector 88. The hollow cylinder 35 is thenin its position of rest 8, 9 and 15, and will remain there until thegovernor forces it to move away. The sliding sleeve 34 controlled by thedriver, is also in the stop position, that is to say, it is in theposition shown by Figures 8, 9 and 15. The

88 oil leaves through the bored channel 41 of the hollow cylinder thechamber ll of the sliding sleeve and, from there, through the channel 53comes between the valves 58 and 55 (Figure 11). The valve 88 having theweakest spring will open first, permitting the oil to pass through thedistributor 51-88 (Figures 1, 9, l2 and 13) into the conduit I1 01 theplate 8 and above the valve I8 (Figures 3 and 4) which it will open topenetrate, through the conduit 28, behind the annular piston 8(Figure 1) The engine turning slowly, the centrifugal piece 22. thrustby its spring 23 will remain close to the centre. The oil which haspenetrated behind the annular piston 8 can thus escape to the outsidethrough the conduit 24 (Figure 5) and the orifice 28; it then passeswithout pressure and without effect into the cy der of the piston 8,but, which is an important point, it will be ready to act almostinstantaneously. since all the conduit and "dead spaces will be filledby its continuous flow.

If, without changing the position of the sliding sleeve 38, the driveraccelerates the engine, it follows that the head piece 22 will beapplied on to its seat and in this way will close the conduits 24 and25. The oil enclosed behind the annular piston 8 will increase inpressure. It will finally displace the piston 8 which, by means of therods I2 (Figure 1), will shift the movable plate 5, compressing thesprings I3. This axial displacement of the piston 8 will be somewhatweak and at first limited by the elastic ring I" of the annular piston8. Actually, this piston ring will engage elastically in thecorresponding groove provided on the piston 8, thus presenting 35(Figure 15), spreads out in certain resistance to the forward movementthere-- of and it will remain in a neutral position. The oil having nooutlet, the pressure will rise and attain a value sufiicient (inpractice about half the total pressure) to act on the valve 55 and passto atmosphere through the orifice I I corresponding thereto (Figure 11).The two clutch d scs I4 and I5 are thus freed.

If now the sliding sleeve 34 is shifted to bring it to its extremeposition shown on Figure 16, it isseen that the oil will pass throughone of the perforated grooves 49 of the sleeve 34 to penetrate throughone of the passagesthat of first speed-into the small chamber 49(Figures 8 and to then act, through the passage II6 on the piston 65controlling the dog clutch sleeve 69. The piston will thus place thelatter in en-' gageme'rit with the dog clutch teeth 92 (Figure 1) of thetoothed wheel 9|. During its stroke the piston '65 will uncover theconduit II1 (Figures 6, 8 and 10) which will take the oil to thedistributor 51-60 and, from there, as previously, to the admission valve26 (Figures 3 and 4) and then behind the annular piston t. The enginerunning at a speed higher than its idle running rate, the head piece 22has closed the oil outlet, so that no escape being provided, thepressure will act with its maximum intensity behind the annular piston9, Overcoming the resistance of the elastic piston ring H4, .andcarrying the slidand 18, thus placing the cylinder '63 in communiingplate 5 along until the latter suificiently compresses the clutch disc[5, to obtain the transmission of the drive. The disc. I4 .remainscompletely free.- The first speed will then be obtained, passing throughthe gears 90--9I, the dog clutch sleeve69, the toothed wheel 88, keyedon the secondary shaft, and the pinion 86 integral with the drivenshaft. It will be noted that the pinion 85 which engages with thetoothed Wheel 81 integral with the secondary shaft, will retate idly onthe firsir shaft. It will be the same with the toothed wheel 93 mountedidly on the secondary shaft, and which will be driven by the pinion 89integral with the shaft 83.

The vehicle then moves forward .As soon as it has attained the intendedspeed, the regulator will act, displacing the sleeve I 98 (Figure 14),which will be immobilised in the first of the grooves I61 by means ofits elastic ring I66. To the resistance of this first groove there willbe added that produced by the looking 43-44 (Figure 14) of the first ofthe grooves 42 of the rod I4I which controls the hollow cylinder of theselector. The distance between the groove and the apertures of theselector bein the same, the bored groove 41 of the hollow cylinder 35will come opposite the passa e 2 (Figure 1'1) of the body 33 of theselector. It will be noted that whatever may be the position of thesliding'sleeve 34 it will be sufiicient for one of its grooves to beopposite the passage 2 to ensure the fiow of the oil which thus passesinto the small chamber 50 (Figure 8) and, from there. through thepassage H8, up to the piston 66 of the cylinder 64.

The piston 66 will thus move, carrying along the dog clutch sleeve 12which, the shaft 82 being free, will engage withouttrouble the gear 85.The disc I4 will thus be rotated idly through the intermediation of thetoothed wheels'90-9I and 61-85, in the same direction as the engine.

but at a lower speed. As soon as the piston 66 has reached the end ofits stroke, which will be rapid in consequence of the small volume to befilled, the pressure in the cylinder 64 will reach in first speed.

cation with the exterior and at the same time. all the conduits leadingto the valve I8 (Figures 3 and 4), the latter under the efi'ect of thereduction of pressure, and acted upon by its spring I9, will close,uncovering the outlet orifice 2|.

Aided. by centrifugal force, the oil will be rapidly evacuated and theannular piston 9 acted upon energetically by the springs I3, will takeup its original position again after having carried with it the movableplate 5 which will compress the clutch disc I4, liberating the disc I5.The disc I4-mounted on the central shaft 82 carrying the dog clutchsleeve 84-12, in engagement with the pinion 85, will drive the wheel 81integralwith the toothed wheel 88, in engagement with the pinion 86 ofthe driven shaft. The second speed is thus in engagement. The piston 65which no longer receives pressure and evacuates its oil by the movementof the needle 15 and under the influence of one of the springs 8|(Figure 1) will take upits neutral position in which it'will be kept bythe locking device of the dog clutch sleeve 69. g

The speed of the vehicle continuing to increase, the regulator, by thesame process as formerly, will bring the groove 41 of the hollowcylinder 35 opposite the passage 3 corresponding to the" orifice 48 ofthe small chamber 5| of Figure 8. The oil under pressure will pass fromthere be hind the piston 65 and will move it, which will place the dogclutcl' sleeve 69 in engagement with the dog clutches 94 of the toothedwheel 93 which is in continuous engagement itself with the pin-f ion 89integral with the clutch disc I5 freed at this moment. Theoil, in thesame way as for the first speed, that is to say, through the conduit II1(Figures 6, 8 and 10) will reach the distributor 51-69, then the valveI8 andarrive finally behind the annular piston 9. It will move thelatter tofree the clutch disc I4 and to compress the disc I5, drivingthe toothed wheel 89. There is thus obtained the third speed.

When the pressure has attained it maximum, that is to say, when thediscI5 is freely driven, the push piece or driver 14 of the cylinder 63will uncover, by its needle 15, the discharge orifices 16 and 18(Figures 6 and 7) of the cylinder 64, thus evacuating the oil which itcontains. The orifice 19 is intended to create a slight leakage of oil,permitting the closing'of the needle 15, of the cylinder 63 as soon asthe admission of oil is interrupted in the cylinder 64. Thepiston. 66

will then again take up its neutral position under groove 41 of thehollow cylinder 35 will come opposite the passage 4 (Figure 18) whichcorresponds to the conduit 48 of the small chamber 52, which is incommunication with the rear of the piston 66 of the cylinder 64. Thedelivery of oil into the cylinder 63 having been cut off, the

driver. 14 and the corresponding needle 15 have again closed. Thepressure can thus increase in the cylinder 64, the piston of which willplace the dog clutch sleeve 12-84in engagement with the driven shaft 3(Figure 1).v When the pressure has attained its maximum in the cylinder64, the

driver 14 will displace the needle 15 which will place in communicationthe orifices 16 and 18 of j the cylinder II, stillfuil of oil. Thelatter. finding an outlet through the orifices II and I0, will escapeand. the pressure failing, the valve II for the supply of oil to thegears will again close, at the same time evacuating the oil containedbehind the annular pistont. The latter energetically acted upon by thesprings it (Figure 1) will follow the movable plate 8 which, liberatingthe disc ll owing to this, will grip the disc I, integral with the shaftif, in direct engagement with the driven shaft 3, through theintermediation of the dog clutch sleeve ll-ll. The apparatus istherefore in fourth speed.

The piston 85 of the cylinder II will take up again its neutral positionas already described.

As will be seen, the transmission will pas successively andautomatically through the four speeds by the operation of the regulatoralone, nevertheless on condition that the driver has placed the slidingsleeve 34 in its position of full speed, as represented on thediagrammatic figures 16 and 18.

Conversely. when the speed of the vehicle diminishes, the regulatorsleeve Ill will move in the reverse direction under the action of itssprings and will bring the groove I! of the hollow cylinder 35 3, 2, I;the operations then take place exactly in the order described forincreasing the speed, as regards each of the descending speedsconsecutively engaged.

If the driver keeps the sliding sleeve in the second speed position, ason t e diagrammatic Figures 18 and 19, it will be seen that the groove41 of the hollow cylinder 3! cannot supply the "stop," first speed" and"second speed" orifices. If, in this position, the driver acceleratesexcesthat the driver can keep the speed he desires by the simple thesliding sleeve ll.

or the third speeds.

It will be noted, furthermore, that when the device is controlling anyspeed whatever, the simple replacement of the sliding sleeve 34 to the"stop" position causes the instantaneous evacuation of the oil, thepassages I, 3, 4 being placed directly in communication with atmosphere(Eigures 8, 9 and except always that of the first speed. Theinstantaneous disengagement of the engine then follows since at the"stop" position the pressure of the oil isrestricted to one-half of itsmaximum value owing to the action of the valve ll.

Figures and 21 show diagrammatically the consecutively opposite thepassa es means for arrangements to be adopted to construct, ac-

three and five speed ons.

hr the three-speed transmission (Figure 20),

cording to the invention, transmissi a single dog clutch controlcylinder is sufficient;

it controls the first and third speeds. The second remains alone on thesecond gear which, disnsag Jotates idly in the case of first and thirdspeeds. This considerably simplifies the conassaaiv dog clutch controlcylinders are necessary, two for double dog clutching and one withsingle dog clutching.

It is possible to construct on the same princi-' ple, a six or morespeeds'transmissicn, the even speeds being always controlled by one ofthe clutches, and the odd speeds by the other.

I claim:

1. An automatic transmission for automotive vehicles comprising anengine shaft, 9, change speed device having two drive shafts, a frictionclutch device for selectively coupling one of the drive shafts to theengine shaft, a driven shaft, a plurality of constant mesh gear wheelsin said change speed device, dog clutches for transmitting power throughsaid shafts and gear wheels,

hydraulic means for selectively actuating the dog clutches resilientmeans for actuating the clutch to couple one of said drive shafts to theengine shaft, hydraulic means for actuating the friction clutch devicecounteracting said resilient means, to couple the other of glue shaft,both of actuated by fluid from the former hydraulic means,

said hydraulic means being under pressure which passes hydraulic meansto the latter so that the operation ofthe hydraulic friction clutchactuating means is delayed until after operation of the hydraulic dogclutch actuating means.

2. An automatic transmission for automotive vehicles comprising anengine shaft, a change speed device having two drive shafts, a frictionclutch device for selectively coupling one of the drive shafts to theengine shaft, spring actuated urging the clutch into position to coupleone drive shaft to the engine shaft, hydraulically' actuated means forovercoming the effect of the spring actuated means'to decouple theensine shaft from aforesaid drive shaft and to couple it to the otherdrive shaft, a driven shaft, constant mesh gear wheels in said changespeed device, dog clutches for transmitting power through said shaftsand gear wheels, hydraulic means for selectively actuating the dogclutches said hydraulically actuated means being operated by fluid underpressure which has passed from said hydraulic means for selectivelyactuating the dog clutches, so that the operation of the friction clutchis delayed until after operation of the dog clutch for a given speedchange.

3. An automatic transmission for automotive vehicles comprising anengine shaft, a change speed device having twodrive shafts, a doubleacting friction clutch having a shiftable element for selectivelycoupling the engine shaft to one of the two drive shafts. a pistonconnected to the shiftable element, a cylinder for said piston, a springurging said piston to a position to couple the engine shaft to one ofthe drive shafts, means for supplying fluid under pressure to thecylinder to displace the piston to a position to couple the engine shaftto the other drive shaft, said cylinder having a ring receiving groove,an expansible ring therein, said piston having a groove to receive saidring when the grooves in the piston and cylinder register to resilientlyretain the piston in intermediate clutch disengaged position, a drivenshaft, constant mesh gear wheels in said change speed devi dog clutchesfor transmitting power through said shafts and gear the dog clutches,and means said drive shafts to the ention of the friction clutch untilafter operation of the dog clutch for a given speed change.-

4. An automatic transmission comprising an engine shaft, 9, change speeddevice having two drive shafts, a double acting friction clutch having ashiftable element, spring means urging the shiftable element to aposition to couple the engine shaft with one of the drive shafts,hydraulically actuated means for shifting the shiftable element againstthe action of the spring to a po sition to couple the engine shaft tothe other drive shaft, a driven shaft, constant mesh gear wheels, shaftsand dog clutches for selectively transmitting power from the driveshafts to the driven shafts, hydraulicmeans for actuating the dogclutches said hydraulically actuated means being operated by fluid underpressure which has passed from said hydraulic means for selectivelyactuating the dog clutch is operated to couple a given drive shaft tothe engine shaft after the dog clutch in the drive connection betweenthe given drive shaft and the driven shaft has been actuated.

5. An automatic transmission comprising an engine shaft, a change speeddevice having two drive shafts, a double acting friction clutch having ashiftable element, spring means urging the shiftable element to aposition to couple the engine shaft with one of thedrive shafts,hydraulically actuated means for shifting the shiftable element againstthe action of the spring to a position to couple the engine shaft to theother drive shaft, a driven shaft, constant mesh gear wheels, shafts anddog clutches for selectively transmitting power from the drive shafts tothe driven shafts, hydraulic means for actuating the dog clutches, anddelayed action means for actuating the friction clutch to couple a givendrive shaft to the engine shaft after the dog clutch in the driveconnection betwen thegiven drive shaft and the driven shaft has beenactuated, a

member rotatable with the engine shaft, a valve carried by saidrotatable member, a spring maintaining said valve in open position torelease liquid from the hydraulically actuated friction clutch elementshifting means, said valve being centrifugally closed upon increase ofrotary speed of said rotatable member to actuate the shiftable elementshifting means.

6. An automatic transmission comprising an shaft, a change speed devicehaving two,

engine drive shafts, a double acting friction clutch having a shiftableelement, spring means urging the shiftable element to a position tocouple the engine shaft with one of the drive shafts, hydraulicallyactuated means for shifting the shiftable element against the action ofthe spring to a position to couple the engine shaft to the other driveshaft, a driven shaft, constant mesh gear wheels, shafts and dogclutches for selectively transmitting power from the drive shafts to thedriven shaft, hydraulic means for actuating the dog clutches, delayedaction means for actuating the friction clutch to couple a given driveshaft to the engine shaft after the dog clutch in the drive connectionbetween the given drive shaft and the driven shaft has beenactuated,'means for controlling the supply of liquid to the dog clutchactuating means comprising a ported cyl-' inder, a ported sleeve havingports adapted to register with those in the cylinder, a hollow pistonhaving a port adapted to register with the clutches, so that thefriction engine shaft, a change register with the ports in the cylinder,and manual means for controlling the position of the sleeve to limit thenumber of cylinder ports-with which the piston port may register.

'7. An automatic transmission comprising an ing a shiftable element,spring means urgingthe shiftable element to a position to couple theengine shaft with one of the drive shafts, hydraulically actuated meansfor shifting the shiftable element against the action of the spring to aposition to couple the engine shaft to the other drive shaft, a drivenshaft, constant mesh gear engine shaft, a change speed device having twodrive shafts, a double acting friction clutch having a shiftableelement, spring means urging the shiftable element to a position tocouple the engine shaft with one of the drive shafts, hydraulicallyactuated means for shifting the shiftable element against the action ofthe spring to a position to couple the engine shaft to the other driveshaft, a driven shaft, constant mesh gear wheels, shafts and dogclutches for selectively transmitting power from the drive shafts to thedriven shafts, hydraulic means for actuating the dog clutches, delayedaction means for actuating the friction clutch to couple a given driveshaft to the engine shaft after the dog clutch in the drive connectionbetween the given drive shaft and the driven shaft has been actuated,the hydraulic means for actuating the dog clutches comprising cylindersand double acting pistons, rods connected to the pistons and forkscarried by the rods for shifting the dog clutches, and springsassociated with the dog clutch fork rods for urging the dog clutches toa neutral disengaged position.

9. A power transmission comprising shaft, a driven shaft, a change speedmechanism having drive shafts and constant mesh gear wheels, means forselectively coupling the said drive shafts of the mechanism to thedriven shaft through said gear'wheels, a friction clutch device foralternatively coupling the driving shaft to the shafts of the changespeed mechanism respectively, fluid pressure reciprocating means foractuating the said coupling means, and the friction clutch device, apump actuated by the driving shaft, conduits connecting said pump withthe reciprocating means, and valves in said conduits, operated by thedriving shaft and the driven shaft, to control the flow of fluid to thereciprocating means.

10. A power transmission comprising'a driving shaft, a driven shaft, achange speed mechanism having drive shafts and, constant mesh gearwheels, means for selectively coupling the said ports in the'sleeve,speed responsive means for I controlling the position of the hollowpiston to progressively bring the port in the piston into drive shaftsto the driven shaft through said gear.

wheels, a friction clutch device for alternatively clutching the drivingshaft to the drive shafts respectively, hydraulic means for operatingthe I speed device having two drive shafts, a double acting frictionclutch, hava driving friction clutch device. hydraulic means to:opersting the said coupling means. and means for controlling the supplyof liquid to the latter hydraulic means comprising s ported cylinder, a.

ported sleeve having ports adapted to register 5 with those in thecylinder, a, hollow piston having a port adapted to resister with theports in the sleeve, means responsive to the speed of the driven shei'tfor controlling the position of the hollow piston to progressively bringthe port in the piston into register with the ports in the cylinder, andmanually operable means for controlling the position of the sleeve tolimit the number of cylinder ports with which the piston port mayregister.

mom's: masses.

